Provenance transition between the Xiamaling and Changlongshan formations in the North China Craton and its paleogeographic implications

Abstract

The Meso-Neoproterozoic strata in the North China Craton provide significant insights into the major Precambrian geological events and the paleogeographic reconstruction. This study investigates the stratigraphy, sedimentology, and provenance analysis of the Xiamaling and Changlongshan formations in the Yanliao Rift Basin. We reveal significant provenance variations and their correlations with regional tectonic events, thereby reconstructing the paleogeographic evolution. The Xiamaling Formation is dominated by shelfal shales interbedded with siltstones and sandstones, whereas the Changlongshan Formation consists of coastal quartzose sandstones. The two formations are in unconformable contact, marked by an abrupt change in sedimentary facies that reflects a change in the regional tectonic setting. Sandstones of the Xiamaling Formation contain abundant felsic volcanic rock fragments, and detrital zircon UPb age spectra display bimodal peaks in the Paleoproterozoic (∼1.8 Ga) and late Paleoproterozoic–early Mesoproterozoic (∼1.6 Ga), with ε_Hf(t) values ranging from −8.6 to +2.5, and − 8.7 to +8.1, respectively. By contrast, Sandstones from the Changlongshan Formation are quartz-dominated and show a single peak of late Neoarchean–early Paleoproterozoic (∼2.5 Ga), and yielded ε_Hf(t) values between − 3.4 and + 5.5. The ∼2.5 Ga zircon ages correspond to continental crustal growth and initial cratonisation. The ∼1.8 Ga peak reflects the collisional amalgamation of the eastern and western blocks of the NCC, forming a unified crystalline basement. The ∼1.6 Ga peak represents magmatic activity in an extensional setting. The paleogeographic evolution of the Yanliao Rift Basin can be reconstructed into three stages: Intracontinental extension (∼1.40–1.32 Ga), tectonic uplift (∼1.32–1.00 Ga), and widespread marine transgression (∼1.00–? Ga).